popmotion

popmotion is a skill for Claude Code, Codex from dylantarre/animation-principles. It costs 19 tokens per session (1,356 once invoked), scanned A, original, MIT.

A Popmotion guide for applying Disney’s 12 animation principles with functional animation code. Popmotion is a JavaScript library for composing animations from smaller functions.

In plain words
What is it for?
Use it to build animated values, keyframes, anticipation sequences, staging effects, overlapping motion, and easing in web interfaces.
Why use it?
It helps developers describe motion as reusable steps, making sequences and updates easier to connect to interface elements.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to build animated values, keyframes, anticipation sequences, staging effects, overlapping motion, and easing in web interfaces.

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Install with agentmods
npx agentmods add skills/dylantarre/animation-principles/popmotion
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add dylantarre/animation-principles --skill popmotion
Clone the repo
git clone --depth 1 https://github.com/dylantarre/animation-principles

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for popmotion

README.md
[![agentmods](https://agentmods.dev/badge/skills/dylantarre/animation-principles/popmotion/github.svg)](https://agentmods.dev/skills/dylantarre/animation-principles/popmotion)
Your own site
<a href="https://agentmods.dev/skills/dylantarre/animation-principles/popmotion"><img src="https://agentmods.dev/badge/skills/dylantarre/animation-principles/popmotion/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for popmotion

Your own site · 80×15
<a href="https://agentmods.dev/skills/dylantarre/animation-principles/popmotion"><img src="https://agentmods.dev/badge/skills/dylantarre/animation-principles/popmotion.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 19 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,356 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk pass 15 Feb 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00019 $0.01356
Opus 5 $0.00010 $0.00678
Sonnet 5 $0.00004 $0.00271
Haiku 4.5 $0.00002 $0.00136

Measured 9d ago against content hash 90157d069cb7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

popmotion scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/09-by-tool-framework/popmotion/SKILL.md · 213 lines

How it starts

The opening of the file, as written. The whole thing — 213 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Popmotion Animation Principles

Implement all 12 Disney animation principles using Popmotion's composable animation functions.

1. Squash and Stretch

import { animate } from "popmotion";

animate({
  from: { scaleX: 1, scaleY: 1 },
  to: { scaleX: 1.2, scaleY: 0.8 },
  duration: 150,
  onUpdate: ({ scaleX, scaleY }) => {
    element.style.transform = `scaleX(${scaleX}) scaleY(${scaleY})`;
  }
});

2. Anticipation

// Wind up then action
animate({
  from: 0,
  to: 10,
  duration: 200,
  onUpdate: v => element.style.transform = `translateY(${v}px) scaleY(0.9)`,
  onComplete: () => {
    animate({
      from: 10,
      to: -200,
      duration: 400,
      ease: easeOut,
      onUpdate: v => element.style.transform = `translateY(${v}px)`
    });
  }
});

3. Staging

animate({
  from: 1,
  to: 0.6,
  onUpdate: v => bg.style.opacity = v
});
animate({
  from: 1,
  to: 1.1,
  onUpdate: v => hero.style.transform = `scale(${v})`
});

4. Straight Ahead / Pose to Pose

import { keyframes } from "popmotion";

keyframes({
  values: [
    { x: 0, y: 0 },
    { x: 100, y: -50 },
    { x: 200, y: 0 },
    { x: 300, y: -30 }
  ],
  duration: 1000,
  onUpdate: ({ x, y }) => {
    element.style.transform = `translate(${x}px, ${y}px)`;
  }
});

5. Follow Through and Overlapping Action

animate({ from: 0, to: 200, duration: 500,
  onUpdate: v => body.style.transform = `translateX(${v}px)` });

animate({ from: 0, to: 200, duration: 500, elapsed: -50, // delay
  onUpdate: v => hair.style.transform = `translateX(${v}px)` });

animate({ from: 0, to: 200, duration: 600, elapsed: -100,
  onUpdate: v => cape.style.transform = `translateX(${v}px)` });

6. Slow In and Slow Out

import { animate, easeInOut, easeIn, easeOut } from "popmotion";

animate({
  from: 0,
  to: 300,
  duration: 600,
  ease: easeInOut,
  onUpdate: v => element.style.transform = `translateX(${v}px)`
});

Read the full file on GitHub · 213 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 213 lines · 19 tokens per session scan A 90157d069cb7

Subscribe to this mod's changes

popmotion is a skill published in the GitHub repository dylantarre/animation-principles (81 stars, last pushed 8mo ago), licensed MIT. It adds 19 tokens to every session and 1,356 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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